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Waterproof Plunger Switch – J4 Series

A Plunger Switch Built to Last – J4 Series

Our high-performance plunger switches use the same patented “double seal” ball carrier design as the J4 ball switch. CPI offers tremendous flexibility in mounting and details of actuator parameters.

These ultra-rugged plunger switches can be configured for the most demanding applications with a wide variety of contact options. Both custom and off the shelf, versions are available.


  • Stainless steel construction
  • Completely submersible (meets IP68)
  • Plunger seals, wiper seals and hardenend actuator configurations
  • Ultra high-temperature capability
  • Normally open and normally closed versions available

Plunger Switch with mounted heatsink for high temp app.

Variable parameters

  • plunger length
  • actuator shape/size
  • mounting thread
  • terminations
  • actuation force
  • travel parameters
  • sealed or vented extension
  • seal configuration
  • normally open and normally closed versions available


  • Hatch / door interlock switch (amphibious military vehicles)
  • valve position sensing (diesel turbochargers, coking ovens)
  • cab down position sensing
  • service door interlock (safety shut-down)
  • hydraulic valve handle position sensing

J4 plunger data sheet thumb
J4 Plunger Data Sheet

Electrical Ratings 28VDC, 5A

Endurance: (28VDC)
5A100,000 cycles
Please contact the factory to discuss your electrical and endurance requirements.
Operating Temperature:
Non-heat sink models-40ºF to 257ºF
Heat sink / Special Designs-40°F to 302°F (up to 400°F plunger area only designs available)